'\" te
.\"  Copyright 1989 AT&T
.\"  Copyright (c) 1996, Sun Microsystems, Inc.  All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH BP_MAPOUT 9F "Nov 15, 1996"
.SH NAME
bp_mapout \- deallocate virtual address space
.SH SYNOPSIS
.LP
.nf
#include <sys/types.h>
#include <sys/buf.h>



\fBvoid\fR \fBbp_mapout\fR(\fBstruct buf *\fR\fIbp\fR);
.fi

.SH INTERFACE LEVEL
.sp
.LP
Architecture independent level 1 (DDI/DKI).
.SH PARAMETERS
.sp
.ne 2
.na
\fB\fIbp\fR \fR
.ad
.RS 7n
Pointer to the buffer header structure.
.RE

.SH DESCRIPTION
.sp
.LP
\fBbp_mapout()\fR deallocates system virtual address space allocated by a
previous call to  \fBbp_mapin\fR(9F)\fB\&.\fR\fBbp_mapout()\fR should only be
called on buffers which have been allocated and are owned by the device driver.
It must not be called on buffers  passed to the driver through the
\fBstrategy\fR(9E) entry point (for example a filesystem). Because
\fBbp_mapin\fR(9F) does not keep a reference count, \fBbp_mapout()\fR will wipe
out any kernel mapping that a layer above the device driver might rely on.
.SH CONTEXT
.sp
.LP
\fBbp_mapout()\fR can be called from user context only.
.SH SEE ALSO
.sp
.LP
.BR strategy (9E),
.BR bp_mapin (9F),
.BR buf (9S)
.sp
.LP
\fIWriting Device Drivers\fR
